Stephen Clark wrote:> Maybe new desktop systems - but what about the tens of millions of old > systems that don't.

If it's an old system, it probably doesn't have working ACPI C-states though. Without that, low HZ does not save you anything. I should have said: 99% of desktops with the capability to do ACPI sleep have at least one USB device attached (usually a mouse).

I do like saving power, which is why I run cpu frequency scaling on every machine I have that supports it. I'm happy because it does its savings without negatively impacting latency or high-load performance. By 2.6.14 dyntick should give us the same thing for HZ, which is why I think changing the maximum value now doesn't make sense.